Meta-analysis of the psychometric properties of the Pain ...
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Meta-analysis of the psychometric properties of the Pain Catastrophizing Scale and
associations with participant characteristics
Claire H B Wheeler1, Amanda C de C Williams2, Stephen J Morley1†
1 Leeds Institute of Health Sciences, Level 10, Worsley Building, Clarendon Way,
Leeds, LS2 9NL, UK
2 University College London, London WC1E 6BT, UK
† died April 2017
Pages: 23
Number of figures: 3 [2 in text; 1 supplementary]
Number of tables: 6 [4 in text; 2 supplementary]
Corresponding author: Claire Wheeler
Mailing address:
Programme in Clinical Psychology, Leeds Institute of Health Sciences
Level 10, Worsley Building
Clarendon Way
Leeds, LS2 9NL, UK
Email: [email protected]
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Abstract
The aims of this study were to review the psychometric properties of the widely used Pain
Catastrophizing Scale (PCS) using meta-analytic methods, and to investigate the relationship
between PCS scores and participant characteristics. A systematic search from 1995 found
229 experimental, quasi-experimental and correlational studies that report PCS scores.
Multivariate regression explored variables related to pain catastrophizing and participant
demographics. Across studies, good internal reliability (α = 0.92, 95% CI 0.91 - 0.93) and
test-retest reliability scores (Spearman ρ = 0.88, 95% CI 0.83 - 0.93) were found for PCS
total scores but not for subscales. PCS scores were unrelated to age or gender, but strongly
related to participants’ pain type, highest in those with generalized pain. Language of the
PCS also affected PCS scores, with further research necessary to determine linguistic,
cultural or methodological (e.g. sampling strategy) influences. Study type influenced PCS
scores with non-randomized controlled trials reporting higher PCS scores than other study
types, but results were confounded with pain diagnosis, as controlled trials were more likely
than quasi-experimental studies to recruit clinical samples. The meta-analytic results provide
insight into demographic influences on pain catastrophizing scores and highlight areas for
further research. The advantages of systematic review and meta-analytic methods to achieve
greater understanding and precision of psychometric properties – in this case, of the PCS –
are applicable to other widely used outcome tools.
Keywords
Outcome measure; PROMS; Systematic review; Reliability
1 Introduction
1.1 Pain catastrophizing
Pain catastrophizing is one of a number of concepts describing the psychological experience
of pain. Beck first described catastrophizing in general as a cognitive error, or ‘an
irrationally negative forecast of future events’ [20] (p.745). Pain catastrophizing is the
forecast of future pain and a person’s inability to divert attention away from the pain [13];
also described by Sullivan and colleagues as ‘an exaggerated negative mental set brought to
bear during actual or anticipated painful experience’ [25] (p.53).
1.2 Established psychometric properties of the PCS
The Pain Catastrophizing Scale (PCS) is widely used as the ‘reference standard
psychometric tool for pain catastrophizing’ [13]. Respondents are asked to rate 13 pain-
related statements on a 5-point Likert scale. During its development, Sullivan and colleagues
investigated the factor structure in a sample of 439 students [23]. Principal components
analysis established that the PCS assessed three related dimensions of magnification
(evaluation of the pain as a threat), rumination (repeated worry) and helplessness (belief that
nothing can help to resolve the pain). Confirmatory factor analysis has since been used in
English and Dutch versions to confirm this three-factor structure compared to a
unidimensional or two-factor structure in students [18], community and pain outpatient
samples [17], and pain-free students, chronic low back pain patients, and fibromyalgia
patients [28]. Overall, these studies demonstrate consistency of the three-factor model of
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pain catastrophizing across participant groups in English and Dutch versions of the
questionnaire.
Existing data on the reliability of the PCS reports adequate to excellent internal validity
scores (coefficient alphas: total PCS = 0.87 - 0.93, rumination = 0.87- 0.91 magnification =
0.66 - 0.75, and helplessness = 0.78 - 0.87; [18; 23]). Pedler reported in a commentary
review that ‘there are currently little data available regarding the test-retest reliability,
sensitivity to change, and clinically meaningful change of the PCS’ and that ‘[f]urther
research investigating these dimensions of the PCS would significantly increase the clinical
utility of this tool’ [19] (p.137). More broadly, there are concerns that many self-report
measures used in health care, including pain, tend to be developed and used in an ad hoc
way, without thorough validation and reliability testing across wide samples of participants
[15] (p.34).
1. 3 Pain catastrophizing scores and personal characteristics
Studies have been conducted to explore potential differences in pain catastrophizing between
people of different ages, genders, from different cultural backgrounds, and with different
pain diagnoses. Such information helps to explain the extent to which the construct of pain
catastrophizing can be viewed as stable across populations. Women tend to score higher than
men [4; 12; 23; 26; 27], although one study reported no sex difference [22]. Older adults
tend to score lower than younger adults [11; 24] but the effect is reversed in adolescents,
where older adolescents score higher than younger [1]. Although a number of studies have
reported pain catastrophizing scores for participants with different pain diagnoses (including
many studies in this review), no review or commentary has compared or combined these.
There have been no studies of the difference in pain catastrophizing scores of participants
using different language versions of the PCS or other measures of pain catastrophizing. Any
disparity in PCS scores of participants using different language versions could be due to
translations of the outcome measure or to cultural differences in the experience and
expression of pain catastrophizing. Existing studies report higher levels of pain
catastrophizing in Chinese Canadians compared to European Canadians [9] and in African-
Americans compared to white Americans [4] using the same language scale. Therefore some
limited evidence from healthy participants suggests the presence of cultural factors in
mediating pain catastrophizing scores.
The rather inconsistent findings from studies on specific participant groups leave open the
question of whether there are systematic age, sex, or other demographic differences in pain
catastrophizing; no comprehensive investigation of such differences in pain catastrophizing
has been attempted.
1.4 Aims of this review
The aims of this review were to systematically obtain data on PCS scores from a wide range
of studies and first to explore the psychometric properties of the PCS using meta-analytic
methods, then to investigate whether there were any clear differences in PCS scores
according to personal characteristics of participants. The review also served to test the use of
meta-analysis to investigate psychometric properties of self-report instruments widely used
in psychological treatment.
1. Methods
1.1 Protocol and registration
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The research protocol for the review and meta-analysis was registered on PROSPERO
(prospective register of systematic reviews) at the University of York’s Centre for Reviews
and Dissemination (CRD), registration number CRD42016032863.
1.2 Eligibility criteria
English language studies reporting baseline PCS scores (those collected before any
intervention) were included in the meta-analysis. Participants in those studies had to be aged
18 or over, could have any health condition or none, and both randomized and non-
randomized studies were included. Included studies were those that reported demographic
and clinical information about participants (age, sex, diagnostic category) and psychometric
data for PCS scores (mean, standard deviation, sample size).
1.3 Search strategy
The search strategy was adapted for Cochrane Library, Cinahl, Embase, PsycInfo, PubMed,
and Web of Science (all 1995-present) by using wildcards and terms relevant to each
database (an example search strategy is included in Suppl. Fig. 1). The last search was run
on 30 November 2015. Requests were sent to authors for data missing from otherwise
relevant studies, resulting in eight responses with eligible scores to 81 requests for missing
PCS data; and no eligible scores for 21 requests sent for missing demographic data.
1.4 Study selection and data collection
One reviewer (CW) screened the title and abstract of the studies retrieved in the database
searches. A random sample (using a random number sequence generator) of 5% of the
papers were screened by title and abstract by a second reviewer (SM) and the inter-rater
reliability calculated. Discrepancies were discussed and resolved. The data collection form
was adjusted following the pilot to allow for pooled data from studies that reported only PCS
subscores, or scores from subgroups but personal data from the whole sample. Data items
extracted from data including participant characteristics, study data, and study type are
presented in Suppl. Table 1.
1.5 Risk of bias in individual studies
A component approach was used to assess the risk of bias in each included study [14].
Relevant components from the Quality Assessment Tool for Observational Cohort and
Cross-Sectional Studies [16] were used in this review and meta-analysis:
1. Was the study population clearly specified and defined?
2. Was the participation rate of eligible persons at least 50%?
3. Were all the subjects selected or recruited from the same or similar populations
(including the same time period)? Were inclusion and exclusion criteria for being in the
study pre-specified and applied uniformly to all participants?
Sensitivity analysis was conducted to ascertain the impact of bias from the above
components on the overall effect sizes found in the meta-analysis. Meta-analysis of effect
size was conducted first for all studies, and then repeated only for studies known to be
eligible (meeting all three risk of bias criteria), following the Cochrane method [7]. There
was unlikely to be a high risk of publication bias in the included data, so no risk of bias
analysis across studies was undertaken.
1.6 Meta-analysis to explore the psychometric properties of the PCS
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2.6.1 Calculating weighted means, standard deviations and reliability alphas of PCS scores
Weighted scores were computed for the PCS mean, standard deviation, and Cronbach’s
alpha for each sample in which these data were available. Weights were based on the
standard error for each sample. The weighted scores were used to compute the mean,
standard deviation, reliability coefficient, confidence intervals, and random effects variance
components for PCS scores across studies.
2.6.2 Reliability estimates
The internal consistency reliability for the PCS and its subscales was calculated by finding
the weighted mean of the Cronbach’s alpha statistics reported in studies using the PCS. The
test-retest reliability for the total PCS scale was calculated using the weighted mean test-
retest reliabilities reported in studies.
2.6.3 Subgroup analysis
Wilson’s macros for SPSS [29] were used to conduct Hedges-Olkin random effects meta-
analysis [5] on participants grouped by pain diagnosis. Hedges and Olkin’s method of meta-
regression was chosen for this analysis because of its coherence with the theory of data used
throughout: that including all available data and accounting for bias through weighting
provides a more comprehensive analysis than excluding data. Hedges and Olkin’s method
uses a pooled variance estimate to standardize the difference between group means. Biases
were corrected based on a sample size statistic using weighted scores.
A Q statistic was calculated to obtain a test of the homogeneity of the effect size (the extent
to which individual effect sizes vary around the mean effect size); it is the standardized sum
of squared differences between each effect size and the mean effect size:
𝑄 =∑(𝑑𝑖 − 𝑑+)
2
�̂�𝑑𝑖2
𝑘
𝑖=1
where k is the number of studies or samples included, d+ is the mean effect size, and
σ2d is the weighted average based on the variance of the unbiased effect sizes
2.6.4 Exploration of the heterogeneity of the mean PCS score across studies
The I2 measure of heterogeneity was calculated for the grand mean PCS score and for the
mean PCS score of diagnostic subgroups. It was necessary to transform the Q value reported
in the original meta-analysis to an I2 value owing to Q having ‘too much power as a test of
heterogeneity if the number of studies is large’ [7] (9.5.2).
The I2 value was calculated from Q as follows:
Ι2 =(𝑄 − 𝑑𝑓)
𝑄
I2 is reported as a percentage, where over 75% indicates substantial heterogeneity between
trials [8].
2.6.5 Use of multiple regression to explore heterogeneity of PCS scores
SPSS version 23 [10] was used to conduct random-effects meta-analysis and meta-
regressions. Multivariate meta-regression was conducted to explore the heterogeneity of
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mean PCS scores across participant groups by testing their association with variables and
other study features.
Wilson’s macro for SPSS was used to employ Hedges and Olkin’s psychometric meta-
analysis method, with results transformed from Fisher’s z scores back to r scores after the
analysis. This method of meta-regression uses a weighted least squares (WLS) procedure
and scores from each study that are weighted by the inverse of the study’s sampling error
bias. Variables entered into the first meta-regression were: pain category (type of pain
diagnosis), mean age of participants, proportion of female participants, year of study (studies
were categorized into ranges of three years), study type, and language of PCS used. A
further meta-regression was then run using pain category as the only variable. Re-running
the meta-regression with this clinically relevant variable meant that more studies were
included, because some studies were excluded on the grounds of missing data — including
those with no data on the gender of participants — in the first meta-regression.
2. Results
3.1 Study selection
220 studies were identified for inclusion in the review and meta-analysis (see Fig. 1 for
searching and screening process). Suppl. Table 2 provides details of reasons for the
exclusion of studies.
[Insert Fig. 1 here] Flow diagram showing the searching and screening stages of papers to be
included in the review and meta-analysis.
Inter-rater reliability was calculated for the screening of papers that was completed by the
two independent raters (CW and SM). There was 90.3% agreement, with a Cohen’s kappa of
0.87 (accounting for agreement due to chance), meeting criteria for reliable inter-rater
agreement [3] (p.56). Discrepancies were discussed and resolved between the raters, with a
conservative approach followed in order to allow for further screening at a later stage.
3.2 Data cleaning and preparation
Data cleaning was conducted to remove double-counted data and data with errors (two
papers in total). Seven further papers contained surprisingly low PCS scores but no evidence
of the source of error; these papers were not removed from the analysis. Instead, meta-
analytic methods were applied to correct for artifacts and error.
3.3 Study characteristics
Data from 220 studies published between 1997 and 2015 was included in the initial analyses.
Included studies were cross sectional, psychometric, case series, randomized controlled and
non-randomized controlled trials, case controlled, and cohort studies. Sample sizes ranged
from 3 to 1,786, and many studies reported PCS scores and related data for two or more
groups of participants so data were collected for 329 groups altogether. The PCS was
represented by 21 languages translated from English.
Mean ages of participants in studies ranged from 19 to 76, with a grand mean age of 45
years, sd = 12 (for both weighted by sample size and unweighted). The grand total number
of participants across included studies was 42,976. The gender ratio was 55:32:13 for male,
female, and participants whose gender was not reported.
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Mean PCS scores across all participant groups ranged from 3.2 to 43.8, with a grand
weighted mean of 20.22 using a random effects model (weighted SD = 10.26, 95% CIs of
mean = 19.30 - 21.14). Unless otherwise stated, ‘PCS score’ refers to the total scale score.
Subscale scores are reported where available. Results of individual studies are presented in
Suppl. Table 1 due to the large number of studies (220) and larger number of participant
groups in the studies (k = 339).
3.4 Risk of bias analysis
Three screening questions were used to assess the risk of bias within studies:
Q1 = Was the study population clearly specified and defined?
Q2 = Was the participation rate of eligible persons at least 50%?
Q3 = Were all the subjects selected or recruited from the same or similar populations
(including the same time period)? Were inclusion and exclusion criteria for being in
the study pre-specified and applied uniformly to all participants?
70 studies fulfilled criteria for all three screening questions. The weighted PCS scores for all
studies included in the review and for just those studies meeting all the risk of bias criteria
were calculated. Subgroup analysis determined the difference in PCS scores between studies
that did and did not meet all of the risk of bias criteria; results are presented in Table 1.
[Insert Table 1 here]
Regression analysis showed the PCS score to be significantly related to whether or not a
study met all risk of bias criteria, B = 16.64, SE = 0.49, 95% CI = 15.68 - 16.60, p < 0.001.
Analysis of variance showed a significant correlation between the type of study conducted
and whether or not the study met all risk of bias criteria, B = 5.62, SE = 0.12, 95% CI =
5.38-5.85, p < .05.
3.5 Meta-analysis to explore the psychometric properties of the PCS
3.5.1 Heterogeneity of the grand mean PCS score
The I2 value of the grand mean PCS score is 98.96%, representing very substantial
heterogeneity between studies. The high I2 value might also suggest that the overall mean ES
is misleading because there are subpopulations of studies represented that have different ES
values; this supports the need to conduct subgroup analysis to further determine the origins
of heterogeneity of mean PCS scores across participant groups (see section 3.5.4).
3.5.2 Reliability
Estimates of the internal consistency of the PCS full scale and subscales were based on
Cronbach’s coefficient alpha[2]. After weighting and averaging reports from 40 studies, the
full scale alpha = 0.92 (95% CI 0.91 - 0.93). PCS subscale data was reported in 21 studies,
with average internal consistency of alpha = 0.89 (95% CI = 0.87 - 0.91) for the rumination
subscale; alpha = 0.77 (95% CI = 0.73 – 0.82) for the magnification subscale; and alpha =
0.88 (95% CI = 0.86 – 0.9) for the helplessness subscale.
Six studies provided eight samples (n = 317) that, when weighted and combined, produced a
mean test-retest reliability of 0.88 (95% CI 0.83 - 0.93, range 0.73 – 0.97), representing good
reliability. The time lapse between the test and retest in included samples ranged from 7 to
135 days. It was not possible to test reliability of scores by time lapse as a number of studies
had a range of intervals between tests rather than a standardized interval (including one
study in which the time lapse ranged between 14-135 days).
3.5.3 Analysis of heterogeneity of PCS scores across participant groups
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Participants from studies included in this meta-analysis were categorized based on their pain
diagnosis. The ‘other’ group consisted of diagnoses that did not fit into one of the specified
categories, including participants with mixed pain diagnoses; these were excluded from
analysis of heterogeneity. The wide spread between branches in the plot of weighted mean
PCS scores suggests substantial heterogeneity in the PCS scores across participant groups
(Fig. 2). Notably, participants with lower limb pain experienced, on average, lower pain
catastrophizing than healthy participants by two points out of a possible score of 52 on the
PCS, and the mean PCS scores of participants with upper limb or upper and lower limb pain
were equivalent to those of healthy participants.
[Insert Fig. 2 here] Forest plot showing the weighted mean ES and confidence intervals of PCS
scores for groups of participants based on pain diagnosis.
3.5.4 Subgroup analysis
Owing to the extent of heterogeneity between PCS scores of participants with different pain
diagnoses, subgroup analysis was conducted to establish the heterogeneity of scores within
diagnoses, to distinguish it from sampling error [6] (Table 2). I2 values ranged from 92.27%
to 99.04%, indicating high levels of heterogeneity within diagnostic groups; 193 groups
(24,546 participants) fell into ‘other’/healthy/groups with mixed or unclear diagnoses and
were excluded from this analysis.
Subgroup analysis between study types showed considerable overlap and homogeneity in
mean PCS scores, with the exception of non-randomized controlled trials which had a higher
mean PCS score than the grand total PCS score (27.55, 95% CI 24.15 - 30.95 compared to
20.22, 95% CI 19.44 - 21). This may be an artifact of data coming from two groups within
one study which recruited participants only if they ‘reported high levels of pain
catastrophizing’ [21] (p.859),
[insert Table 2 here]
3.5.5 Meta-regression of PCS scores
Multivariate meta-regression analysis was conducted to establish the association between
PCS scores and characteristics of study participants (age, sex, diagnostic category) and study
design (language of PCS, type of study, year of study publication). After exclusion because
of missing data 277 groups were included in the analysis. Diagnostic category of
participants, language, and type of study were all significantly associated with the mean PCS
score obtained (Table 3). In a further meta-regression conducted with the variable of
diagnostic category, this variable was again significantly associated with the mean PCS
score (all 329 participant groups were included in this analysis; see Table 4).
[insert Tables 3 and 4 here]
Significantly higher or lower mean scores occurred for some non-English language versions
of the PCS, notably for the Cantonese version of the PCS (weighted mean score for
Cantonese was 36.3, compared to a mean of 18.48 for English versions, β 15.31, p = .002).
The Cantonese scores were based on one study using the Cantonese language version.
3. Discussion
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4.1 Psychometric properties of the PCS
The review included 220 studies of a total of 329 participant groups (42,976 clinical and
non-clinical participants) with a mixture of pain diagnoses, age, and gender distributions,
with a range of study types. Systematic review and meta-analytic methods were used to
synthesize existing data by establishing and refining the known psychometric properties of
the PCS using a far larger data set than previous studies. Internal consistency and test-retest
reliability of the overall score and of the rumination subscale (but not of magnification or
helplessness subscales), were all >0.85, encouraging confidence in use (see also Sullivan
and colleagues [23]). The higher test-retest reliability found in this meta-analysis than
previously [23] could be explained by shorter intervals between testing, or the inclusion in
the current meta-analysis of stabler non-clinical samples alongside clinical samples. The
psychometric findings on the PCS from a much larger evidence base may in part allay
concerns over the ‘ad-hoc’ creation of psychometric self-report scales in health and
psychology [15].
4.2 The relationship between PCS scores and participant characteristics
Subgroup analysis showed that PCS scores did not differ systematically with age or gender,
again encouraging confidence in use,,particularly in the light of contradictory results of
previous studies [1; 4; 11; 12; 22; 23; 24; 26; 27]. However, different pain diagnoses were
associated with differences in PCS scores, and while this could be mediated by the
association of pain catastrophizing scores with pain intensity reports [20], it is more likely
that different pain problems are associated with different specific worries, and those with
diagnoses that are difficult to establish or contested (such as fibromyalgia [31]) may more
consistently generate catastrophic thinking. This requires further investigation.
The findings of this review reveal differences in PCS scores across populations and
languages, but given the complexity of cultural and linguistic translation, it would be
premature to try to interpret these findings. They do, however, serve as a reminder that
simply translating a questionnaire does not guarantee that its psychometric properties remain
the same as in the original language.
4.3 Strengths and limitations of the review
Strengths and limitations of this review are considered within a broader synthesis of the use
of meta-analysis to establish psychometric properties of a self-report scale. Studies were
included in this review if PCS use was reported in the study abstract, so it is likely that some
studies were missed that only identified PCS use in their Methods. A replication could
search all papers likely to be potentially eligible; this would likely be over 3000 papers.
However, for this review, maximum use of included studies was made by including all data
available per analysis. Additionally, the principle of assessing rather than selecting against
methodological deficiency allowed the inclusion of all studies regardless of risk of bias,
examined instead by sensitivity analysis and by weighting scores using a random effects
model in the meta-analysis.
In this review, participants were categorized according to a single pain diagnosis, but many
people with chronic pain have more than one pain condition, and could not be fitted into a
pain diagnosis category. Studies used different ways of categorizing pain or describing pain
diagnoses, meaning that data were matched to ‘best fit’ for this meta-analysis, for example
‘low back pain’, ‘acute low back pain’, ‘chronic low back pain’, and ‘persistent non-specific
low back pain’ were classified as ‘lumbar pain’ although there may have been differences in
diagnosis and threshold for classification in the different studies. The high proportion of
‘healthy’ participants in included studies who were students limits the generalizability of the
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results to the general population of ‘healthy’ people without a pain diagnosis but with a
wider age range. This is not unique to this review.
It is possible that the decision to include other language versions of the PCS introduced
biases and inaccuracies owing to different psychometric properties of these versions. The
decision was justified by the widespread international use of the PCS, highlighting the need
for further validation studies of the translated versions of the questionnaire.
The risk of bias screening was completed by one author (CW). Optimally, a second author
would duplicate the screening and results would be compared. Otherwise, established
protocols for systematic review and meta-analysis were followed [14]. Meta-analytic
methods were used to correct for measurement artifacts within included studies by weighting
scores to obtain more accurate estimated effect sizes.
Samples used in the regression analysis were not fully independent in that, frequently, more
than one participant group was included from a single study. This increased the number of
groups available to analyze, but the results should be treated with caution due to this non-
independence of samples.
Even excellent reliability does not imply validity of the concepts, and there are theoretical
concerns about notions such as ‘magnification’ that imply contrast with a ‘correct’ amount
of pain experience that are inconsistent with current understanding of pain psychology.
Conclusions drawn in this review about psychometric properties of the PCS cannot be used
as proof of validity of the concept of pain catastrophizing.
Overall, this review demonstrates a comprehensive attempt to identify relevant papers and a
systematic method of discussing and deciding on inclusion and exclusion of studies. The use
of meta-analysis across a large sample of studies allowed for exploration of narrow variance
of PCS scores. The findings provide greater support for evidence from previous individual
studies on the reliability and validity of the PCS.
4.4 Implications for clinical practice and research
Studies in this meta-analysis highlighted that the PCS is widely used for research and
clinical practice. Current normative values and clinical cut-off scores are based on a sample
of 851 injured workers, 75% of whom had a soft tissue back injury [23] (p. 6). This meta-
analysis demonstrated that percentile scores as used to establish this clinical-cut-off vary
between clinical groups based on pain diagnoses. This brings into question the concept of a
clinically relevant score: should the clinical cut-off for pain catastrophizing be based on
percentiles across pain diagnoses, or is it more pertinent to establish a cut-off using
comparisons with others who have a similar pain condition? Either of these options is likely
to be preferable to using the current clinical cut-off based on one study of a sample of
injured workers. Further research is necessary to establish percentile PCS scores either
across or within pain conditions using raw scores from multiple studies.
Changes from baseline PCS scores following treatment such as surgery or psychological
therapy were not considered in the scope of this review. However, the more precise
estimates provided here for internal consistency and test-retest reliability allows calculation
of reliable change beyond that attributable to random variation across time. Meta-regression
following systematic review helped to refine participant variables that did (language; pain
diagnosis) and did not (age; gender) relate to PCS scores over a wide population. This helps
to define variables of interest for future studies of the PCS and pain catastrophizing.
Finally, the methods used in this meta-analysis could be applied to any self-report scale
(PROM) used in clinical psychology or other fields. The use of meta-analysis to establish a
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stronger evidence base for the psychometric properties of questionnaires is encouraged in
order better to understand sources of variance. This would strengthen the use of those self-
report scales, as well as encouraging discarding those that fail standards of reliability and
validity. Such research could help to introduce greater precision and theoretical justification
to the ever-increasing aggregation of concepts and scales.
4. Conclusion
This is the first psychometric meta-analysis of the PCS, and the first investigation of the PCS
on such a large scale. Meta-analytic methods in this review confirmed the reliability of the
overall scale and refined psychometric and normative properties. The PCS as a full scale is
concluded to be a reliable measure. Caution is urged in the clinical interpretation of scores
due to differences in scores between people with different pain diagnoses, and potential
linguistic or cultural influences on PCS scores should be considered when using different
language versions of the scale. It is hoped that results from this review will encourage the
use of meta-analytic methods to establish more accurate psychometric properties of other
psychological and self-report scales.
Acknowledgements
Professor Robert West, Dr Gary Latchford and Dr Andrew Prestwich are acknowledged for
their technical help with statistical analysis and interpretation.
Conflicts of interest
The authors have nothing to disclose.
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assessment-tools. Accessed 30 Jul 2018.
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159.
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14
Fig 1
Records identified through database searching
(n = 7,614)
Scre
enin
g
Incl
ud
ed
Elig
ibili
ty
Iden
tifi
cati
on
Records after duplicates removed (n = 3,721)
Records screened (n = 3,721)
Records excluded (n = 3,292)
Full-text articles assessed for eligibility
(n = 429)
Full-text articles excluded (n = 209)
Studies included in meta-analysis
(n = 220)
PsycINFO: 1171
EMBASE: 1584
PubMed: 953
CINAHL: 658
Cochrane Library: 334
Web of Science: 2914
16
Table 1. Weighted mean PCS scores and confidence intervals for all studies included in the
meta-analysis, for studies meeting all risk of bias criteria, and for studies that did not meet all
risk of bias criteria.
Included studies N Weighted
mean PCS
score
95% CI
of mean
Weighted sd of
PCS score
95% CI of
sd
All studies 220 20.2 19.3-21.1
10.3 10.0-10.5
Studies meeting all
risk of bias criteria
70 22.8 20.9-24.6 10.8 10.4-11.2
Studies not meeting
all risk of bias criteria
150 19.1 18.2-20.1 10.0 9.7-10.3
17
Table 3. Association between covariates in meta-regression and the grand mean PCS score.
Variable Type
III sum
of
squares
Degrees
of
freedom
Mean
square
F Significance
level
Amount
of
variance
accounted
for (eta
squared)
Mean age of
participants
118.00 1 118.00 3.15 .077 0.01
Percentage of female
participants
31.52 1 31.52 0.84 .360 0.00
Diagnostic category
of participants
5644.69 8 705.59 18.83 <.001 0.39
Language of PCS
administered
3870.13 19 203.69 5.44 <.001 0.30
Type of study 1586.30 7 226.61 6.05 <.001 0.15
Year range of
publication*
299.21 4 74.80 2.00 .096 0.03
* Year of publication was categorized into groups of 3-year duration
18
Table 4. Regression of variable ‘diagnostic category of participants’ onto the grand mean
PCS score.
Univariate
model
Weighted least squares meta-regression model
95% confidence
interval
Variable p β Lower
bound
Upper
bound
t p
Diagnostic
category of
participants
<.001
Healthy Index
Generalised pain 17.24 14.41 20.07 11.99 <.001
Head and neck pain 6.70 2.61 10.80 3.22 .001
Cervical and
thoracic pain
6.16 0.56 11.76 2.16 .031
Upper limbs or
upper and lower
limb pain
-3.40 -6.23 -0.57 -3.36 .019
Trunk pain 11.26 6.42 16.10 4.58 <.001
Lumbar pain 6.96 4.74 9.17 6.18 <.001
Lower limbs -2.16 -6.33 2.01 -1.01 .309
19
Other or mixed
diagnosis
8.25 6.44 10.07 8.94 <.001
Supplementary files
Suppl. Figure 1. Search strategy used to identify potentially relevant studies from the
Cochrane Library.
1. pain catastrophi* scale*
2. pain catastrophi* measure*
3. pain catastrophi* questionnaire*
4. catastrophization [MeSH terms]
5. pain measurement [MeSH terms]
6. pain NEAR/3 catastrophi*
7. #4 AND #5
8. #1 OR #2 OR #3 OR #6 OR #7
20
Suppl. Table 1. Characteristics of studies included in the review and meta-analysis.
Study
ID
First
author
Year
of
public
ation Study type Language Participant group
Sample
size
Mean
age Sd age
M:F
participa
nts
Mean
PCS
score
Sd PCS
score
3 Barke 2015 Psychometric German Chronic back pain 182 51 10.5 54:128 19.7 12.1
6 Iwaki 2012 Cross Japanese Chronic pain 160 51 16.4 48:112 33.9 10.2
7 Karstens 2015 Psychometric German Lower back pain 228 42 11 120:128 16.7 10.5
8 Kikuchi 2015 Cross Japanese
Whiplash neck injury
pain and/or low back
pain 956 45 10.4 679:277 24 11.8
9 Kim 2013 Psychometric Korean
Degenerative spinal
disease 72 66 8.1 27:45 24.1 12.2
10 Kjogx 2014 Cross Danish Chronic headache 57 49 15.1 57:0 16.9 10.4
10 Kjogx 2014 Cross Danish Chronic headache 161 45 15.2 0:161 22.5 12
10 Kjogx 2014 Cross Danish Healthy participants 118 22 7.2 118:0 10.3 6.7
21
10 Kjogx 2014 Cross Danish Healthy participants 129 22 5.2 0:129 12.3 8.7
11 Koo 2015 Psychometric Korean Chronic pain 64 41 14.5 23:41 18.8 11.9
12 Kraljevic 2012 Cross Croatian Chronic pain 100 55 10 36:64 31 12.6
12 Kraljevic 2012 Cross Croatian
Healthy participants
(adult children) 100 30 10 50:50 21.8 12.2
12 Kraljevic 2012 Cross Croatian
Healthy participants
(spouse) 85 60 10 51:34 25.6 13.4
16 Lim 2006 Psychometric Chinese Chronic pain 120 / / 50:70 31.9 11.1
17 Lopes 2015 Psychometric
Brazilian
Portuguese Acute low back pain 131 67 7.1 10:121 29.2 13.1
18 Man 2007 Case Chinese Chronic pain 45 / / 15:30 33.7 12.1
19 Maric 2011 Cross Croatian
Healthy participants
6th yr medical
students 53 24 1.8 10:43 16.8 9.9
19 Maric 2011 Cross Croatian
Healthy participants
1st yr medical
students 137 19 1.7 47:90 19.2 7.9
22
19 Maric 2011 Cross Croatian
Healthy participants
1st yr economics
students 245 19 1.7 86:159 19.7 9.1
19 Maric 2011 Cross Croatian
Healthy participants
5th yr economics
students 86 23 1.7 22:64 19.8 10.1
20 Matsudaira 2014 Psychometric Japanese Low back pain 1786 49 / 900:886 24.6 10.9
21 Matsuoka 2010 Case Japanese
Burning mouth
syndrome 46 60 9.6 2:44 28.2 9.7
23 Meyer 2008 Psychometric German Low back pain 111 49 16 36:75 17.6 10.5
25 Mohd Din 2015 Psychometric Malay
Healthy participants
military 303 21 1.8 258:45 19.2 10.2
29 Morris 2012 Psychometric Africaans
Fibromyalgia,
Africaans speaker 41 / / / 37 11.4
29 Morris 2012 Psychometric
English
South
African
Fibromyalgia,
English speaker 33 / / / 38.2 11.5
23
29 Morris 2012 Psychometric Xhosa
Fibromyalgia, Xhosa
speaker 19 / / / 34.2 8.5
30 Ning 2008 Psychometric Cantonese Chronic pain 224 42 10.3 120:104 36.3 10.9
35 Penhoat 2014 Cross French Rheumatoid arthritis 86 59 13.7 27:59 17 13.6
35 Penhoat 2014 Cross French Spondyloarthritis 54 43 10.1 37:17 20.8 12.1
37 Rodero 2010 Psychometric Spanish Fibromyalgia 205 50 9.7 19:186 32.4 12.8
38 Rodero 2012 Psychometric Spanish Fibromyalgia 250 52 8.5 11:239 24.3 13.6
40 Roelofs 2003 Psychometric Dutch Fibromyalgia 401 48 10.1 22:379 20.3 11.5
41 Roelofs 2002 Psychometric Spanish
Healthy participants
students 271 19 1.4 54:226 14.3 7.9
42 Rogulj 2014 Cross Croatian
Burning mouth
syndrome 30 66 9.2 5:25 28.4 15
43 Sehn 2012 Psychometric
Brazilian
Portuguese
Chronic
musculoskeletal pain 384 50 17.1 67:317 30.6 11.7
44 Severijns 2002 Cross Dutch Hip/knee pain 582 / / / 12.1 10.4
44 Severijns 2002 Cross Dutch Low back pain 754 / / / 12.2 10.4
24
44 Severijns 2002 Cross Dutch
Neck/shoulder/high
back pain 880 / / / 12.3 10.3
44 Severijns 2002 Cross Dutch
Elbow/wrist/hand
pain 480 / / / 13 10.8
44 Severijns 2002 Cross Dutch Ankle/foot pain 284 / / / 13.5 11
44 Severijns 2002 Cross Dutch
Healthy participants,
no pain 1164 / / / 8.2 8
46 Suren 2014 Cross Turkish Preoperative patients 165 39 13.9 91:74 16.1 11.5
48
Van
Damme 2002 Psychometric Dutch Low back pain 162 42 11.6 63:99 22 9.3
48
Van
Damme 2002 Psychometric Dutch Fibromyalgia 100 45 9.1 20:80 24.8 12.2
48
Van
Damme 2002 Psychometric Dutch
Healthy participants
students 550 19 1.4 147:403 16.6 7.8
49 Volz 2013 Series
Brazilian
Portuguese
Chronic myofascial
pain syndrome 24 48 12.6 0:24 34.2 9.2
50 Wong 2015 Series Chinese Chronic pain 226 45 9.2 77:149 26.7 14.7
25
51 Wong 2011 Psychometric Chinese
Chronic
musculoskeletal pain 208 41 11.3 95:113 29 14.3
54 Yap 2008 Psychometric Chinese
Chronic
nonmalignant pain 130 / / 54:76 29.1 5.5
56 Park 2015 Cross Korean
Temporomandibular
disorder 155 39 15.2 44:111 17.3 12.6
65 Adachi 2014
Cross-
sectional study Japanese Chronic pain 176 64 15.1 80:96 26.5 12.2
66 Aerts 2015 Cohort study English
Secondary provoked
vestibulodynia 175 28 5.5 0:175 26.7 10.7
66 Aerts 2015 Cohort study English
Primary provoked
vestibulodynia 94 26 5.5 0:94 27.6 10
67 Akhter 2014 Other English Healthy participants 28 35 9.5 20:8 15.4 11.4
69 Alappattu 2015 Cross English Pelvic pain 14 40 / 0:14 23.1 12.4
69 Alappattu 2015 Cross English Healthy participants 28 30 / 0:28 9.2 9.7
70 Albert 2015 Cohort study French
Musculoskeletal
disorder 43 41 12 20:23 19 12
26
71 Al-Kaisy 2015
Retrospective
cohort stud English
Chronic neuropathic
pain of upper or
lower limbs 11 46 12 5:6 33 11
75 Archer 2015 Cohort English
Lower extremity
trauma 134 45 15 70:64 14 13
77 Baranoff 2015 Cohort English
Anterior cruciate
ligament
reconstruction 44 27 9.4 27:17 11.3 9.8
78 Barnhoorn 2015
RCT
secondary data
analysis Dutch
Complex Regional
Pain Syndrome type
1 35 43 16.9 6:29 22.8 11.7
78 Barnhoorn 2015
RCT
secondary data
analysis Dutch
Complex Regional
Pain Syndrome type
1 21 46 16.5 5:16 24.9 14.8
81 Beck 2014 Series English
Orthodontic
elastomeric
separators 20 24 3.4 9:11 14.6 7.6
27
86 Beneciuk 2013 Series English Low back pain 146 41 13.5 57:89 16.8 12.1
87 Beneciuk 2012
Secondary
analysis English
Acute and subacute
low back pain 108 37 14.5 39:69 16.3 11.2
90
Bhaskarac
harya 2015 Cross English
Pain-free participants
with a history of
chronic trigeminal
neuropathic pain 12 64 9.5 0:12 15.9 13.3
90
Bhaskarac
harya 2015 Cross English
Healthy participants
control group 15 62 6.9 4:11 7.1 11.7
91 Billis 2013 Cross English
Non-specific low
back pain 106 36 15.9 43:63 19.4 7.9
92 Block 2008 Cross English Chronic pain 43 44 12.7 17:26 23.9 11.8
94 Bond 2015 Series English Migraine and obesity 105 38 8 0:105 22.7 10.8
96 Borg 2012 Cross Dutch Dyspareunia 33 27 6.8 0:33 15.3 7.3
96 Borg 2012 Cross Dutch Vaginismus 35 28 5.8 0:35 22 9.3
28
96 Borg 2012 Cross Dutch
Healthy participants
without sexual
complaints 54 27 6.7 0:54 17.4 9.1
98 Bostick 2013 Series English
Whiplash associated
disorder 72 39 14 15:57 24.7 9.4
99 Bot 2014 Psychometric English
Upper extremity
diagnoses 164 51 15 75:89 5.3 6.9
101 Bot 2013 Series English
Post patients hand
surgery
nonresponders to
later survey 69 48 16 37:32 3.2 4.9
101 Bot 2013 Series English
Post patients hand
surgery responders to
later survey 35 56 17 10:25 5.6 7.2
102 Bot 2014 Cross English
Painful conditions of
the upper extremity 130 52 16 62:68 8.7 9.4
29
103 Bot 2013 Cohort English
Arm, shoulder and
hand disability 1204 53 16 511:693 6.8 8.4
108 Brandini 2011 Case English
Temperomandibular
disorder 15 31 10.7 0:15 12.7 10.6
108 Brandini 2011 Case English Healthy participants 14 29 5 0:14 11 8.4
114 Bryson 2014 Cross English
Chronic pain and
insomnia 111 44 10.9 35:76 30.6 14.7
116 Buitenhuis 2008 Series English
Postwhiplash
syndrome 140 36 12 45:95 12.9 11.3
119 Calley 2010 Cross English Low back pain 80 47 11.5 34:46 13.9 10.1
120 Campbell 2010 Case English
Temperomandibular
joint disorder 48 34 12 7:41 14.3 9.2
120 Campbell 2010 Case English Arthritis 43 55 9.7 16:27 15.4 12
120 Campbell 2010 Case English Healthy participants 84 34 14.6 51:33 9.5 9
123 Carroll 2011 Case English
Palliative care
patients on opioid
treatment 20 58 10 9:11 19.8 13.3
30
125 Carvalho 2014 Series English
Labour and
successful vaginal
delivery 39 34 5 0:39 16 9
128 Casey 2015 Cohort English Whiplash injury 246 43 14.6 54:192 16.1 13.2
130 Cebolla 2013 Psychometric Spanish Fibromyalgia 251 52 8.4 10:241 24.3 13.6
135 Chatkoff 2015 Cross English
Muskuloskeletal
pain, adaptive copers 26 / / / 20.3 13.9
135 Chatkoff 2015 Cross English
Muskuloskeletal
pain, dysfunctional 15 / / / 27.8 12.8
135 Chatkoff 2015 Cross English
Muskuloskeletal
pain, dysfunctional 28 / / / 32.5 10.1
138 Chibnall 2005 Psychometric English
Low back injury,
compensation
claimants 1475 / / 919:556 25.4 12.1
140
Choobmasj
edi 2012 Cross Arabic
Healthy volunteers
pregnant 300 28 5.9 0:300 29.3 11.8
31
142 Chung 2012 Series Chinese
Major depressive
disorder 91 48 9.5 18:73 23.7 13.1
143 Chung 2015 Other Chinese
Major depressive
disorder 137 50 9.6 28:109 24.6 11.3
149 Cosic 2013 Cohort Croatian Parous 69 30 / 0:69 16.1 13.2
149 Cosic 2013 Cohort Croatian Nulliparous 80 24 / 0:80 23.9 12.6
151 Curran 2010 Series English
Provoked
vestibuladynia 8 30 10.6 0:8 24.8 7.9
153 Darchuk 2010 Series English
Non-cancer pain,
geriatric patients,
older 78 67 5.6 28:50 25.6 13.7
153 Darchuk 2010 Series English
Non-cancer pain,
geriatric patients,
middle aged 230 48 5.3 43:187 26.2 12.1
153 Darchuk 2010 Series English
Non-cancer pain,
geriatric patients,
younger 141 30 6.2 25:116 27.3 12.6
32
154 Darnall 2012 Cross English
Chronic pain,
incarcerated women 159 39 11.5 0:159 27.1 11.8
155 Darnall 2014 Series English
Chronic pain
outpatients 57 50 12.2 16:41 26.1 10.8
159 Davidson 2008 Psychometric English Chronic pain 126 50 14.2 40:86 22.4 13.2
161 Davis 2015 Series English
Provoked
vestibulodynia 222 31 10.9 0:222 28.2 10.8
165 de Boer 2014 Cross Dutch
Chronic pain,
outpatients 89 51 15.5 34:55 22.4 13
172 Demoulin 2010 Psychometric Dutch
Chronic low back
pain 99 42 9.4 60:39 22.2 10.3
173 D'Eon 2004 Psychometric English
Healthy participants,
students, men 229 21 3.7 229:0 20.6 9.6
173 D'Eon 2004 Psychometric English
Healthy participants,
students, women 276 20 4.1 0:276 26.4 9.4
176 Dimitriadis 2014 Psychometric Greek Chronic neck pain 45 36 14.5 13:32 21.4 12
33
179 Dixon 2004
Other
experimental English
Healthy participants,
college students, men 91 / / 91:0 16.6 7.9
179 Dixon 2004
Other
experimental English
Healthy participants,
college students,
women 112 / / 0:112 19.2 9.7
185 Durosaro 2008 Series English Erythromelalgia 8 43 16.8 1:7 29.9 6.8
191 Fabian 2011 Cross English
Healthy participants,
college students, men 24 / / 24:0 13.8 7.8
191 Fabian 2011 Cross English
Healthy participants,
college students 62 / / 24:38 15.9 8.2
193 Feldman 2015 Cross English
Patients undergoing
total knee
arthroplasty 316 66 8.7 130:186 12 10.7
195 Fernandes 2002 Psychometric Norwegian
Non-specific low
back pain 90 48 11.7 38:52 13.6 9.2
197 Fitzcharles 2014 Cross English Fibromyalgia 246 48 10.4 22:224 29.3 12.2
199 Flink 2009 Series Swedish Prepartum 82 / / 0:82 19.6 9.5
34
200 Forsythe 2008 Series English
Preoperative patients
before total knee
arthroplasty 55 69 8.4 20:35 9.8 8.7
201 Fritz 2015 Rct English
Recent-onset low
back pain 112 37 10.2 59:53 13.8 10.1
201 Fritz 2015 Rct English
Recent-onset low
back pain 108 38 10.4 46:62 13.9 11
202 Gagnon 2013 Series English Chronic pain 101 44 8.2 64:37 28 15
203 Gandhi 2010 Psychometric English Hip osteoarthritis 100 63 10.6 50:50 16.6 13.7
203 Gandhi 2010 Psychometric English Knee osteoarthritis 100 67 8.4 31:69 17.3 13.3
205
Garcia-
Campayo 2010 Psychometric Spanish Fibromyalgia 250 45 7.2 21:229 30.8 11.7
206 Herbst 2010 Series English Adiposis dolorosa 10 48 3.6 4:6 28.2 3.5
207 Gautier 2011 Cross Other Chronic pain, men 26 41 8 26:0 23.7 9.4
207 Gautier 2011 Cross Other Chronic pain, women 24 39 10.6 0:24 27.1 13.1
209 George 2011 Psychometric English Low back pain 80 47 11.5 34:46 14.1 10.1
35
212 Geva 2013 Case English
Healthy participants
triathletes 19 40 12.1 11:8 16.5 9
212 Geva 2013 Case English
Healthy participants
controls 17 37 11.1 7:10 20.8 12
214 Gilliam 2010 Cross English Healthy participants 97 25 2.8 41:56 19.5 8.8
215 Goodin 2011 Other English
Healthy participants,
college students,
Caucasian American 86 / / / 13.2 8.6
215 Goodin 2011 Other English
Healthy participants,
college students,
African American 28 / / / 15.4 11.5
215 Goodin 2011 Other English
Healthy participants,
college students,
Asian American 35 / / / 15.9 9.9
219 Grotle 2012 Psychometric Norwegian
Pelvic girdle pain in
pregnancy and after
delivery 87 34 5.3 0:87 13.5 8.7
36
223 Hayashi 2015 Series Japanese Neck-shoulder pain 87 51 16.4 35:52 32.1 10.6
223 Hayashi 2015 Series Japanese Headache 62 51 18.3 14:48 33.7 10.3
223 Hayashi 2015 Series Japanese
Low back/lower limb
pain 142 57 15 58:84 33.7 10.1
224 Hegarty 2014 Cross English
Post-enucleation,
persistent pain 8 61 18.1 6:2 3.6 6.8
224 Hegarty 2014 Cross English
Post-enucleation, no
pain 9 61 18.2 3:6 6.8 15.9
228 Hiebert 2012 Series English
Low back pain,
active duty US navy
personnel 253 32 7.9 188:65 11.1 9.9
229 Hirakawa 2014 Series Japanese
Patients three weeks
post surgery 90 76 6.3 20:70 13 9.3
230 Hirsch 2008 Psychometric English
Healthy participants,
undergraduate
students 100 21 1.7 44:66 18.6 9.2
37
235 Hooten 2009 Cohort English
Chronic pain, never
smoked, male 134 47 13.6 134:0 23.1 12.3
235 Hooten 2009 Cohort English
Chronic pain, never
smoked, female 500 46 4.8 0:500 24.8 13
235 Hooten 2009 Cohort English
Chronic pain, former
smoker, female 203 50 12.9 0:203 26 11.9
235 Hooten 2009 Cohort English
Chronic pain, former
smoker, male 91 54 13.5 91:0 26.2 11.1
235 Hooten 2009 Cohort English
Chronic pain,
smoker, female 225 43 10.9 0:225 27.6 13.2
235 Hooten 2009 Cohort English
Chronic pain,
smoker, male 88 42 12 88:0 31.5 11
238 Horsham 2013 Cross English
Experienced trauma
but no PTSD 91 / / / 13.6 7.8
238 Horsham 2013 Cross English
Control (no
experience of
trauma, no PTSD) 71 / / / 8.6 4.3
38
238 Horsham 2013 Cross English Ptsd 87 / / / 25.3 8
241 Kadimpati 2015 Cross English Chronic pain 595 47 13.7 173:422 26.7 11.2
242 Kao 2012 Cross Other
Postmenapausal
dyspareunia sufferers 182 57 5.4 0:182 16.1 13.2
244 Karayannis 2013 Cross English Low back pain 19 43 13.2 6:14 14.4 8.2
246 Karsdorp 2009 Cross Dutch Fibromyalgia 409 48 10.2 21:388 20.3 11.4
252 Khan 2012 Series English
Cardiac surgery,
preoperative 64 66 11.1 54:10 11.7 11.1
253 Kim 2015 Psychometric Korean
Degenerative lumbar
spinal stenosis, men 35 64 12.8 35:0 19.9 13.3
253 Kim 2015 Psychometric Korean
Degenerative lumbar
spinal stenosis,
women 60 66 9.6 0:60 27.9 11.5
254 Kim 2014 Cross Korean
Lumbar spinal
stenosis 155 65 12.4 57:98 24.9 12.8
256 Kleiman 2011 Psychometric English
Patients scheduled
for major surgery 444 46 10.2 174:270 16.5 10.5
39
257 Koele 2014 Series Dutch
Chronic widespread
musculoskeletal pain 165 44 12.9 22:143 17.5 9.4
260
Kristjansd
ottir 2013 Rct Norwegian
Chronic widespread
pain 66 44 11.2 0:66 20.8 9.5
260
Kristjansd
ottir 2013 Rct Norwegian
Chronic widespread
pain 69 45 11.1 0:69 21.2 10.3
263 La Touche 2014 Cross Spanish
Chronic craniofacial
pain 192 46 13.1 60:132 23.9 8.9
264 Lame 2008 Psychometric Dutch Chronic pain 50 55 13.1 20:30 30.2 11.7
265 Lariviere 2010 Cohort English
Chronic low back
pain, women 13 35 9 0:13 15 13
265 Lariviere 2010 Cohort English
Chronic low back
pain, men 14 43 10 14:0 26 10
268 Lee 2008 Psychometric English Healthy participants 189 27 8 99:90 11.4 7.4
269 Lemieux 2013 Cross French Dyspareunia 179 31 10 0:179 28.6 9.7
270 Leonard 2013 Cross English
Chronic
musculoskeletal pain 57 56 15.1 16:41 25.7 14.2
40
271 Lin 2013 Other Chinese Healthy participants 15 26 11.2 6:9 19.2 8.1
272
Lindenhov
ius 2008 Rct English
Lateral elbow pain,
placedo, lidocaine
only 30 51 10 12:18 20.8 8.5
272
Lindenhov
ius 2008 Rct English
Lateral elbow pain,
dexamethasone 27 50 8 10:17 21.8 10.5
274 London 2014 Cohort English
Atraumatic hand or
wrist condition 256 56 12.6 75:181 11.8 8.9
275 Louw 2015 Series English
Patients scheduled
for lumbar surgery 10 47 16.2 3:7 25.4 13.5
280 Lukkahatai 2013 Cross English
Fibromyalgia
patients with fatigue 9 41 7.3 0:9 17 9.8
282 Theunissen 2014 Psychometric Dutch
Preoperative
hysterectomy 192 46 7.8 0:192 13.1 8.5
282 Theunissen 2014 Psychometric Dutch
Patients undergoing
day surgery,
preoperative 75 53 15.3 31:44 14 8.8
41
282 Theunissen 2014 Psychometric Dutch Mixed inpatient 1490 56 15.5 702:788 16.5 12.7
283 Martel 2013 Series English Chronic pain, women 35 50 8.9 0:35 24.3 13.6
283 Martel 2013 Series English Chronic pain, men 20 49 10.5 20:0 24.5 10.4
284 Martin 2010 Cross English
Chronic pain patients
pre-surgery 208 47 9.7 83:124 19.3 7.9
285 Martinez 2012 Cross Spanish Healthy participants 200 40 11.3 0:200 13.7 10
288
Masselin-
Dubois 2013 Cohort French
Breast cancer
patients pre-surgery 100 55 12.1 0:100 14.6 11.4
288
Masselin-
Dubois 2013 Cohort French
Total knee
arthroplasty patients
pre-surgery 89 69 8.9 35:65 19.4 11.2
290
McLoughli
n 2011 Cross English
Women with
fibromyalgia 39 43 12.1 0:39 13.9 7.7
290
McLoughli
n 2011 Cross English
Women healthy
controls 40 41 9.1 0:40 8.5 7
291
McWillia
ms 2007 Psychometric English
Healthy participants,
university students 278 20 4 145:136 15.7 9
42
292
McWillia
ms 2015 Psychometric English Chronic pain 201 47 10.3 74:127 25.8 12
293 Meeus 2010 Rct Dutch
Chronic fatigue
syndrome and
chronic widespread
pain, experimental
group 24 38 10.6 2:22 18.2 6.9
293 Meeus 2010 Rct Dutch
Chronic fatigue
syndrome and
chronic widespread
pain, control group 24 42 10.2 6:18 21.8 8.9
294 Meyer 2009 Cross German
Chronic low back
pain 78 50 17 26:52 19.2 10.3
295 Michael 2004 Series English Chronic pain 86 42 10.4 46:40 27 13.3
298 Monticone 2014 Rct Italian
Chronic low back
pain, control group 10 57 14.4 6:4 23 4
43
298 Monticone 2014 Rct Italian
Chronic low back
pain, experimental
group 10 59 16.4 3:7 25 6
300 Monticone 2014 Rct Italian
Spondylolisthesis
and/or lumbar spinal
stenosis,
experimental group 65 59 11.8 21:44 24.8 9.3
300 Monticone 2014 Rct Italian
Spondylolisthesis
and/or lumbar spinal
stenosis, control
group 65 56 14.2 30:35 27 8.7
301 Monticone 2015 Psychometric Italian Chronic neck pain 118 48 15.9 40:78 18.5 9
302 Moore 2013 Cross English
Healthy participants,
male 70 23 6.6 70:0 18 8.6
302 Moore 2013 Cross English
Healthy participants,
female 119 24 5.9 0:119 20.5 8.3
44
303 Moseley 2004 Series English
Chronic low back
pain, group 2 46 35 7 16:30 16 5
303 Moseley 2004 Series English
Chronic low back
pain, group 1 75 36 6 38:37 16 6
304 Moseley 2004 Rct English
Chronic low back
pain, experimental
group 31 42 10 13:18 19 6
304 Moseley 2004 Rct English
Chronic low back
pain, control group 27 45 6 12:15 20 6
307 Moustafa 2015 Rct English
Fibromyalgia and
C1-2 joint
disfunction 60 51 7 33:27 42.5 3
307 Moustafa 2015 Rct English
Fibromyalgia and
C1-2 joint
disfunction 60 54 8 35:25 43.8 3.6
308 Munoz 2005 Cross Other Chronic pain 149 59 15 42:107 20.9 16.3
45
309 Nakamura 2014 Cross Japanese
Chronic pain,
receiving folk
remedy 108 46 13.8 33:75 23.2 9.9
309 Nakamura 2014 Cross Japanese
Chronic pain, seen at
medical facility 213 55 14.8 84:129 26.5 10.3
310 Naugle 2014 Other English
Healthy participants,
young adults, men 12 / / 12:0 5.2 4.1
310 Naugle 2014 Other English
Healthy participants,
young adults, women 15 / / 0:15 9.3 4.1
312 Nickel 2010 Case English
Interstitial
cystitis/painful
bladder syndrome 207 50 15.1 0:207 21.3 12.6
312 Nickel 2010 Case English
Healthy participants,
control group 117 48 13.5 0:117 9.9 9.2
314 Nieto 2011 Cross Spanish
Whiplash associated
disorders 147 34 10.4 42:105 17.9 9.9
46
316 Nishigami 2015 Case Japanese
Chronic low back
pain, shrunken
perceived body
image 12 62 12.4 4:8 19.6 11.4
316 Nishigami 2015 Case Japanese
Chronic low back
pain, expanded
perceived body
image 12 57 16.7 4:8 21.4 6.5
316 Nishigami 2015 Case Japanese
Chronic low back
pain, normal
perceived body
image 18 65 11.2 8:10 21.6 7
317 Novak 2011 Cross English
Upper-extremity
nerve injury 158 41 16 105:53 16 15
318 Novak 2012 Cross English
Brachial plexus
nerve injury 61 40 17 41:20 15 14
47
319 Novak 2013 Psychometric English
Upper extremity
nerve injury 157 41 16 104:53 16 15
321 Ogunlana 2015 Cross English
Nonspecific low
back pain 275 52 13.4 110:165 24 10.4
325 Osman 2000 Psychometric English Pain outpatients, men 26 31 8.7 26:0 19.6 11.4
325 Osman 2000 Psychometric English
Pain outpatients,
women 34 33 10.7 0:34 24.3 8.8
325 Osman 2000 Psychometric English
Healthy participants,
men 85 36 10.8 85:0 11.1 8
325 Osman 2000 Psychometric English
Healthy participants,
women 130 35 12.2 0:130 15.7 10.9
326 Osman 1997 Psychometric English
Healthy participants,
students, study 2,
men 59 20 2.5 59:0 10.9 7.8
326 Osman 1997 Psychometric English
Healthy participants,
students, study 3,
women 86 / / 0:86 11.7 8.4
48
326 Osman 1997 Psychometric English
Healthy participants,
students, study 1,
men 93 / / 93:0 11.9 8
326 Osman 1997 Psychometric English
Healthy participants,
students, study 1,
women 195 / / 0:195 14.6 9.6
326 Osman 1997 Psychometric English
Healthy participants,
students, study 2,
women 161 20 3.7 0:161 15 9.5
326 Osman 1997 Psychometric English
Healthy participants,
students, study 3,
men 86 / / 86:0 18.4 9.6
327
Papaioann
ou 2009 Series Greek
Degenerative disc
disease 61 51 14.5 25:36 21.7 13.2
328 Parr 2012 Psychometric English Healthy participants 126 24 9.8 51:75 9.8 7.8
330 Pavlin 2005 Series English
Anterior cruciate
ligament injury 48 31 1.2 27:21 14.4 8.3
49
331 Pearson 2009 Cross English
Whiplash-associated
disorder 14 37 10.8 8:6 17 14.4
333 Philips 2014 Cross English
HIV-associated
sensory
polyneuropathy 28 51 8.4 25:3 23.7 12.6
333 Philips 2014 Cross English
HIV-positive but
with no HIV-
associated sensory
polyneuropathy 38 48 8.9 32:6 14.1 11.8
334 Pincus 2008 Psychometric English
Non-cancer chronic
pain 243 44 12 110:133 29.3 12.3
335 Plazier 2015 Series Other Fibromyalgia 11 42 8.3 0:11 20.6 8.8
337 Prugh 2012 Series English
Throwing athletes
with elbow injuries 3 21 2.5 3:0 5 7
338 Pukall 2007 Series English
Vulvar vestibulitis
syndrome 8 26 5.7 0:8 18.1 6.9
50
339 Raak 2006 Cross Swedish
Whiplash associated
disorder 17 51 11.3 1:16 19.9 7.8
339 Raak 2006 Cross Swedish Healthy participants 18 45 10.2 1:17 13 5.6
340 Radat 2013 Cohort French
Chronic peripheral
neuropathic pain 182 60 13.8 87:95 28 13
341 Reyahin 2014 Psychometric English Knee osteoarthritis 212 65 10.1 49:163 6.6 7
342 Riddle 2011 Nrct English
Patients scheduled
for knee arthroplasty,
control group 45 61 9.9 12:33 25.8 11.1
342 Riddle 2011 Nrct English
Patients scheduled
for knee arthroplasty,
experimental group 18 64 11.5 6:12 29.3 8.9
343 Ring 2005 Cross English
Pain, single discrete
pain complaint 56 55 15 22:34 14 11.3
343 Ring 2005 Cross English
Pain, vague diffuse
idiopathic arm pain 51 41 15 14:37 20.4 11.7
51
344 Rivest 2010 Cross English
Whiplash associated
disorder 37 35 12.2 16:21 16.4 14.2
346 Robles 2012 Series English Healthy participants 76 25 5.2 27:49 14.4 9.8
347 Rodero 2008 Series Spanish Fibromyalgia 8 / / 1:7 25.3 10
348 Rodero 2010 Cross Spanish
Fibromyalgia, under
2 years chronicity 46 47 9.8 / 30.9 14.3
348 Rodero 2010 Cross Spanish
Fibromyalgia, 2-4
years chronicity 59 48 11 / 33.1 11.9
348 Rodero 2010 Cross Spanish
Fibromyalgia, more
than 4 years
chronicity 223 50 10.5 / 33.1 11.6
349 Roh 2014 Series Korean
Patients post-surgery
distal radius fractures 121 53 14 54:67 22 9
350 Roh 2015 Series Korean
Patients with
surgically treated
hand fractures 93 45 12 55:48 23 8
52
351 Rosenberg 2015 Series English
Chronic pain of trunk
and/or limbs 386 56 14.5 156:230 30.2 12.1
353 Roth 2007 Series English
Patients pre-surgery,
total knee
arthroplasty 63 70 8.8 29:34 7.1 7.3
355
Ruiz-
Parraga 2014 Cross Spanish
Chronic
musculoskeletal pain,
non-trauma-exposed 117 43 11.7 36:81 20.5 6.5
355
Ruiz-
Parraga 2014 Cross Spanish
Chronic
musculoskeletal pain,
trauma-exposed
without post
traumatic stress
symptoms 119 44 11.2 36:83 21 6.9
355
Ruiz-
Parraga 2014 Cross Spanish
Chronic
musculoskeletal pain,
trauma-exposed with 110 47 12.5 30:80 31.9 10.3
53
post traumatic stress
symtoms
356
Ruschewe
yh 2011 Cross German
Healthy participants,
younger group 88 27 4.8 29:59 15.5 8.8
356
Ruschewe
yh 2011 Cross German
Healthy participants,
older group 46 60 5.2 20:26 20.2 11.2
357 Sanchez 2011 Cross Spanish Fibromyalgia 74 47 8.1 4:70 25.4 11.8
358 Sansone 2014 Cross English Primary care patients 239 46 15 88:151 13.2 13.1
366 Scott 2014 Series English
Whiplash injury,
occupationally
disabled 148 37 9.2 / 22.3 10.8
367 Selvarajah 2014 Cross English Diabetic neuropathy 142 61 11.2 80:62 18.7 9
373 Sterling 2008 Cross English Whiplash injury 30 38 11.5 7:23 18.8 12.7
373 Sterling 2008 Cross English Healthy participants 30 30 8.8 6:24 12.2 5.1
376 Sullivan 2005 Cross English
Post-herpetic
neuralgia 12 70 / 4:8 20.7 9.2
376 Sullivan 2005 Cross English Diabetic neuropathy 19 57 / 15:4 25.5 11.7
54
376 Sullivan 2005 Cross English
Post-surgical/post-
traumatic pain 49 47 / 22:27 26.2 11.9
380 Sullivan 2002 Cross English Whiplash injury 65 35 7.1 25:40 32.2 10.9
381 Sullivan 2002 Cross English
Chronic pain,
chronicity less than 2
years 44 36 7.5 / 29.1 11.3
381 Sullivan 2002 Cross English
Chronic pain,
chronicity more than
4 years 51 39 8.3 / 31.3 10.7
381 Sullivan 2002 Cross English
Chronic pain,
chronicity 2-4 years 55 34 9.2 / 31.9 11.3
382 Sullivan 2000 Other English
Healthy participants,
college students, men 53 / / 53:0 16.6 7.7
382 Sullivan 2000 Other English
Healthy participants,
college students,
women 55 / / 0:55 20.5 8.9
55
383 Sullivan 2000 Other English
Healthy participants,
college students, men 38 / / 38:0 17.6 10.3
383 Sullivan 2000 Other English
Healthy participants,
college students,
women 42 / / 0:42 26.6 10.4
384 Sullivan 2008 Rct English
Post-herpetic,
diabetic, or post-
traumatic neuralgia 22 52 16.3 11:10 24.2 10.8
384 Sullivan 2008 Rct English
Post-herpetic,
diabetic, or post-
traumatic neuralgia 24 55 12.6 15:9 25.2 11.4
385 Sullivan 1998 Cross English
Soft-tissue injuries to
the neck, shoulders
or back following
work or motor
vehicle accidents 86 36 7.8 27:59 28 12.8
56
388
Swinkels-
Meewisse 2006 Series Dutch
Acute lower back
pain 93 45 11.5 45:48 18.8 12
391 Tetsunaga 2015 Series Japanese
Intractable chronic
pain, adaptive group 37 56 14 15:22 33.7 6.6
391 Tetsunaga 2015 Series Japanese
Intractable chronic
pain, dropout group 16 50 15 5:11 37.5 6.8
392 Teunis 2015 Series English
After distal radius
fracture surgery 116 55 14 31:85 17 5.9
393 Thorn 2004 Other English
Healthy participants,
students, men 90 / / 90:0 15.3 9.8
393 Thorn 2004 Other English
Healthy participants,
students, women 129 / / 0:129 21.9 10.4
394
Tomkins-
Lane 2015 Series pilot English
Lumbar spinal
stenosis 10 68 6.7 4:6 7.9 5.7
395 Torres 2015 Rct Spanish
Fibromyalgia,
experimental group 24 53 10.3 5:19 23.5 13.5
57
395 Torres 2015 Rct Spanish
Fibromyalgia,
control group 24 53 7.7 4:20 28.3 12.3
396 Touche 2015 Cohort Spanish
Headache attributed
to
temporomandibular
disorder, mild neck
disability 42 41 12.9 25:17 15.8 4
396 Touche 2015 Cohort Spanish
Headache attributed
to
temporomandibular
disorder, moderate
neck disability 41 44 10.9 15:26 17.1 3.8
396 Touche 2015 Cohort Spanish Healthy participants 39 41 10 13:26 5.5 1.8
398 Trompetter 2015 Rct Dutch Chronic pain 79 52 11.8 19:60 17.6 10.2
398 Trompetter 2015 Rct Dutch Chronic pain 82 53 13.3 19:63 18.6 9.5
398 Trompetter 2015 Rct Dutch Chronic pain 77 53 12 19:58 19.1 9.6
399 Turner 2013 Cross English Rheumatoid arthritis 32 55 15.7 8:24 21 11
58
399 Turner 2013 Cross English Healthy participants 28 47 11.8 7:21 8 8
400 Vaisy 2015 Cross German Low back pain 20 33 9.6 19:11 13.9 8.9
401
van
Damme 2014 Cross English
Persistent non-
specific low back
pain, good
performers on
muscle endurance
task 120 42 8.1 / 15.9 9.3
401
van
Damme 2014 Cross English
Persistent non-
specific low back
pain,
underperformers on
muscle endurance
task 212 42 8.1 / 18.5 9.8
404
van
Ittersum 2011 Series Dutch Fibromyalgia 41 / / 3:38 15.2 11.4
59
405
van
Ittersum 2014 Rct Dutch Fibromyalgia 52 46 9.8 4:48 23 12.1
405
van
Ittersum 2014 Rct Dutch Fibromyalgia 53 48 9.1 3:50 24 11.9
407 Vancleef 2006 Cross Dutch
Healthy participants,
university local
community 48 22 4.4 12:36 14.2 7.8
410 Vincent 2014 Rct English
Obese adults with
chronic low back
pain 17 69 7.3 5:12 11.5 12.6
410 Vincent 2014 Rct English
Obese adults with
chronic low back
pain 14 68 6.4 5:9 12.5 11.7
410 Vincent 2014 Rct English
Obese adults with
chronic low back
pain 18 69 7.1 6:12 13.2 12.7
413 Vowles 2013 Cross English Chronic pain 334 46 11.4 126:208 25.3 17.3
60
414 Vranceanu 2014 Series English
One to two months
after muskuloskeletal
trauma surgery 136 48 17.3 63:73 19.1 8.7
415 Vranceanu 2015 Rct English
Musculoskeletal
trauma within last 1-
2 months,
experimental group 24 / / / 14.8 9.9
415 Vranceanu 2015 Rct English
Musculoskeletal
trauma within last 1-
2 months, control
group 10 / / / 15.7 11.2
418 Walker 2014 Cross English Spinal pain 183 55 14.5 116:67 15.1 10.6
420 Walton 2013 Psychometric English
Patients with work-
related pain
conditions 235 37 10 88:147 21.7 10.9
61
421 Watson 2008 Cross English
Isolated, discrete
upper-extremity
condition 134 50 13 83:51 19.3 7.3
423 Witvrouw 2009 Series Dutch
Preoperative, total
knee arthroplasty 43 61 / 17:26 20.2 9.7
424 Wong 2013 Cross Chinese Chronic pain 224 46 9.9 100:124 24.6 14.3
425 Zhao 2012 Other English
Healthy participants,
experimental group 13 30 4.9 6:7 8.2 6
425 Zhao 2012 Other English
Healthy participants,
control group 13 30 3.4 6:7 12.6 13.6
62
Suppl. Table 2. Reasons for papers not included in the database at title/abstract and full text stages.
Stage of screening Number of
papers
excluded
Reason for exclusion
Abstract and title screening (total of
3,292 papers excluded at this stage) 1079 Not enough info in title/abstract to judge inclusion and exclusion criteria
639 Not relevant (not a study/no use of PCS. Includes errata)
437 PCS not used
401 Conference or meeting abstract, not a paper
355 Relevant review/meta-analysis/editorial comment/letter/theoretical paper
210 Use of PCS, but for children/adolescents (under 18yrs); or child study (may or may not use PCS),
or parent version of PCS
100 Study protocol or dissertation abstract
34 Data only (full paper coded separately)
12 Animal study
63
10 Conference proceedings/posters
7 Book chapter or book review
3 Uses 4-question version or another modified version of PCS
2 Uses spouse version only (PCS-S)
2 Uses a modified PCS
1 Guidelines (not a study)
Full text screening (total of 209 papers
excluded at this stage) 52 PCS scores not reported
49 Meeting abstract
22 Insufficient data
22 Foreign language paper
13 All or some participants were under 18 years old
11 Duplicates data from another (included) study
10 Modified version of PCS used
9 Not a study (e.g. correction to a publication; figure; protocol only)
64
6 No baseline
5 Not peer reviewed
4 Single case study
3 Misuse of PCS (for example changes to instructions)
2 Literature/systematic review
1 Paper not retrieved
Data cleaning 1 Double counting of data (paper reporting data duplicating that of another paper)
1 Implausible data (contains data above or below possible scores)
1 Data double-counted